Vaishnava Samhita. Narayana Muni Charitam. Vol III Book VI Chp 21 Shloka 7

आत्मानात्मविचारेण रहितां ज्ञाननिष्ठया  |
मन्यन्ते निष्फलां भक्तिं केचिदद्वैतवादिनः || 

Some who reveal in the philosophy of Advaita consider that bhakti bereft of contemplation on the abstract details of Aatma and inanimate things and a love for developing such abstract thinking is futile